High-purity Pfa Filter Tank With Ptfe Seal, Outer Tank for Collecting High-purity Crystals in an Inert Gas Environment

PFA Filter Tank (with PTFE Flange Sealed Outer Tank)

The core material of this filter tank is PFA (Perfluoroalkoxy), and the outer tank is usually made of PTFE (Polytetrafluoroethylene). It is a high-purity and corrosion-resistant container specially used in the semiconductor and fluorochemical industries.

PTFE Flange Sealed Outer Tank - Excellent Anti-leakage Sealing Design

This structure avoids the risks of corrosion and pollution that may be caused by the contact between metal flanges and the medium. It ensures the sealing of the entire system under inert gas environment and negative/positive pressure conditions, and prevents the leakage of toxic and harmful gases and the intrusion of air (oxygen and water vapor).

The PFA material is usually translucent, which allows operators to directly observe the reaction, crystallization, filtration, and liquid level inside the tank, facilitating process control. Compared with metal tanks of the same size, PFA equipment is lighter in weight, making it easier to install and maintain.

Performance Characteristics of PFA Filter Tank

1. Strong Corrosion Resistance

It has aqua regia-level corrosion resistance and can withstand strong acids, strong alkalis, strong oxidants, and organic solvents. This is crucial for handling various highly toxic and corrosive media in the fluorochemical process, such as hydrogen fluoride, chlorine trifluoride, tungsten hexafluoride, etc.

2. No Metal Ion Contamination: Different from stainless steel equipment, PFA/PTFE materials do not precipitate metal ions (such as Fe, Ni, Cr, etc.), ensuring the high purity of the products.

3. High Cleanliness and No Contamination: The PFA surface is very smooth, not easy to adhere to materials, and has a very low surface energy, preventing the attachment of crystal particles and making it easy to clean and completely discharge.

4. In ultra-pure chemicals or crystal slurries, the high-purity PFA material effectively avoids cross-contamination.

5. Excellent Thermal Stability: PFA can withstand temperatures from -200 to 250℃ under normal pressure, meeting the temperature changes that may be involved in the processes of crystal reaction, crystallization, filtration, drying, etc.

6. Suitability in Inert Gas Environment: The entire structure of the equipment (tank, flange, seal) is made of inert materials and will not react with the inert gases such as nitrogen and argon filled in, preventing the oxidation of crystal products or their reaction with water vapor.

Applications of PFA Filter Tank

1. Receiving and Temporary Storage of Crystal Slurries: As a transfer container, it receives the slurries (a mixture of solid crystals and mother liquor) containing the target crystals discharged from the reaction kettle or crystallizer.

2. Filtration and Washing: Usually, a filtration device (such as a PFA filter plate or filter bag) can be connected to the bottom of the tank. By vacuuming or pressurizing, the mother liquor is separated from the crystals. After separation, high-purity solvents can be added to the tank to wash the crystals multiple times to remove impurities.

3. Inert Gas Protection: During the entire process of receiving, filtering, and washing, inert gas is continuously filled to ensure that the crystals sensitive to oxygen and moisture (such as many organic semiconductor materials and certain fluorides) will not deteriorate.

4. Drying (partial design): Some filter tanks are designed with heating jackets or can be connected to hot nitrogen, which can directly perform preliminary drying on wet crystals after filtration and washing.

5. Sealed transfer: After filtration and washing, the crystals remain in the tank. Due to its fully enclosed design, the entire tank can be directly disassembled and transferred to the next process (such as a drying oven or a packaging room), isolated from the air throughout the process.